feat(tui): display tool execution status in minimal TUI

TUI now creates a NativeAgent with tool registry/executor and uses
agent.process() for message handling. Tool calls display status lines
showing tool name, args, and success/error result. Falls back to
direct model client when agent is not configured.

src/frontends/tui/minimal.ts

@@ -2,6 +2,7 @@ import * as readline from 'node:readline';
 import type { ManagedSession } from '../../session/index.js';
 import type { ModelClient, TokenUsage } from '../../models/types.js';
 import type { ModelRouter, ModelTier } from '../../models/router.js';
+import type { NativeAgent } from '../../backends/native/agent.js';
 import { parseCommand, getHelpText, resolveModelAlias, getCommandCompletions, getCommandTooltip, type Command } from './commands.js';
 import { renderMarkdown } from './markdown.js';
 import type { ModelConfig } from '../../config/schema.js';
@@ -32,6 +33,7 @@ export interface MinimalTuiConfig {
   modelClient: ModelClient;
   modelRouter?: ModelRouter;
   systemPrompt: string;
+  agent?: NativeAgent;
   onFullscreen?: () => void;
   onTransfer?: (target: string) => void;
   localProviders?: Record<string, ModelConfig>;
@@ -285,12 +287,22 @@ export class MinimalTui {
   }
 
   private async handleMessage(content: string): Promise<void> {
-    this.config.session.addMessage({ role: 'user', content });
-
     // Print Flynn label before response
     process.stdout.write(`\n${colors.orange}${colors.bold}Flynn:${colors.reset}\n`);
 
     try {
+      // Use agent if available (supports tool loop)
+      if (this.config.agent) {
+        const response = await this.config.agent.process(content);
+        const rendered = renderMarkdown(response);
+        console.log(rendered);
+        console.log();
+        return;
+      }
+
+      // Fallback: direct model client (no tool support)
+      this.config.session.addMessage({ role: 'user', content });
+
       // Try streaming if available
       if (this.config.modelClient.chatStream) {
         let fullContent = '';

src/tui.ts

@@ -2,17 +2,40 @@ import { loadConfig } from './config/index.js';
 import { SessionStore, SessionManager } from './session/index.js';
 import { AnthropicClient, OpenAIClient, OllamaClient, LlamaCppClient, ModelRouter } from './models/index.js';
 import { MinimalTui, startFullscreenTui } from './frontends/tui/index.js';
+import { NativeAgent } from './backends/index.js';
+import { ToolRegistry, ToolExecutor, allBuiltinTools } from './tools/index.js';
+import { HookEngine } from './hooks/index.js';
 import type { Config } from './config/index.js';
 import { resolve } from 'path';
 import { homedir } from 'os';
-import { existsSync, mkdirSync } from 'fs';
+import { existsSync, mkdirSync, readFileSync } from 'fs';
 
 const CONFIG_PATH = process.env.FLYNN_CONFIG
   ?? resolve(homedir(), '.config/flynn/config.yaml');
 
-const SYSTEM_PROMPT = `You are Flynn, a helpful personal AI assistant. You are direct, concise, and helpful. You can help with a variety of tasks including answering questions, providing information, and having conversations.
+// ANSI color codes for tool status display
+const toolColors = {
+  reset: '\x1b[0m',
+  dim: '\x1b[2m',
+  cyan: '\x1b[36m',
+  green: '\x1b[32m',
+  red: '\x1b[31m',
+};
 
-Keep responses focused and avoid unnecessary verbosity. Use markdown formatting when it improves readability.`;
+function loadSystemPrompt(): string {
+  const paths = [
+    resolve(process.cwd(), 'SOUL.md'),
+    resolve(import.meta.dirname, '../SOUL.md'),
+  ];
+
+  for (const soulPath of paths) {
+    if (existsSync(soulPath)) {
+      return readFileSync(soulPath, 'utf-8');
+    }
+  }
+
+  return 'You are Flynn, a helpful personal AI assistant. Be direct, concise, and helpful. Use markdown when it improves readability.';
+}
 
 function createModelRouter(config: Config): ModelRouter {
   const models = config.models;
@@ -99,10 +122,40 @@ async function main() {
   const sessionStore = new SessionStore(resolve(dataDir, 'sessions.db'));
   const sessionManager = new SessionManager(sessionStore);
   const modelRouter = createModelRouter(config);
+  const systemPrompt = loadSystemPrompt();
+
+  // Initialize tool registry and executor
+  const hookEngine = new HookEngine(config.hooks);
+  const toolRegistry = new ToolRegistry();
+  for (const tool of allBuiltinTools) {
+    toolRegistry.register(tool);
+  }
+  const toolExecutor = new ToolExecutor(toolRegistry, hookEngine);
 
   // Get TUI session
   const session = sessionManager.getSession('tui', 'local');
 
+  // Create agent with tools and tool status display
+  const agent = new NativeAgent({
+    modelClient: modelRouter,
+    systemPrompt,
+    session,
+    toolRegistry,
+    toolExecutor,
+    onToolUse: (event) => {
+      if (event.type === 'start') {
+        const argsStr = event.args ? ` ${toolColors.dim}${JSON.stringify(event.args)}${toolColors.reset}` : '';
+        process.stdout.write(`${toolColors.cyan}> ${event.tool}${toolColors.reset}${argsStr}\n`);
+      } else if (event.type === 'end' && event.result) {
+        const icon = event.result.success ? `${toolColors.green}done` : `${toolColors.red}error`;
+        const detail = event.result.success
+          ? `${toolColors.dim}(${event.result.output.split('\n').length} lines)${toolColors.reset}`
+          : `${toolColors.dim}${event.result.error ?? 'unknown error'}${toolColors.reset}`;
+        process.stdout.write(`  ${icon}${toolColors.reset} ${detail}\n`);
+      }
+    },
+  });
+
   const cleanup = () => {
     sessionStore.close();
   };
@@ -118,7 +171,7 @@ async function main() {
       session,
       modelClient: modelRouter,
       modelRouter,
-      systemPrompt: SYSTEM_PROMPT,
+      systemPrompt: systemPrompt,
       model: config.models.default.model,
       onExit: cleanup,
     });
@@ -130,7 +183,8 @@ async function main() {
       session,
       modelClient: modelRouter,
       modelRouter,
-      systemPrompt: SYSTEM_PROMPT,
+      systemPrompt,
+      agent,
       localProviders: config.models.local_providers,
       currentLocalProvider: config.models.local?.provider,
       onTransfer: (target) => {
@@ -156,7 +210,7 @@ async function main() {
         session,
         modelClient: modelRouter,
         modelRouter,
-        systemPrompt: SYSTEM_PROMPT,
+      systemPrompt,
         model: config.models.default.model,
         onExit: cleanup,
       });